Traditionally, grain farmers have used a number of implements to prepare the soil and seed the crop. Generally a grain farmer passes the land once with a cultivator equipped with harrows to till the land. Thereafter, the farmer changes equipment and passes the land again, using an air hoe drill equipped with an air seeder machine. Thus, it has been necessary to make at least two passes over the land.
As soil conservation practices become more popular in several areas, a need has developed for an implement which can cut furrows, seed, fertilize and cover the seed in one pass. No-till or zero-till direct seeding is accomplished by a cultivator equipped with narrow openers, and a means to convey seed and fertilizer pneumatically behind the openers, followed by a series of packers. However, certain conditions of the soil and certain crops do no permit this type of seeding. For example, when there are many weeds on the land, a cultivator must be equipped with sweeps which completely cultivate the land, followed by harrows, and the application of seed and fertilizer. Finally, the soil is packed with coil packers. This type of seeding is termed direct seeding but is not considered no-till. At other times an operator may wish simply to do general tillage of the land, and this can be accomplished with the use of a cultivator equipped with sweeps, and harrows following behind. If the land is to be seeded later, an air hoe drill or other seeding device is pulled over the field.
In light of the foregoing, there has become a need to have one implement which can function interchangeably as a direct seeder or a cultivator. Thus there has developed a need to have a cultivator which, when equipped with harrows, performs the total tillage requirements. When the same cultivator is equipped with narrow openers, mounted packers, and an air seeder, it serves as a one pass direct seeding operation with on-row packing. In order to accomplish this dual function a need has arisen to have a quick means of interchanging harrow assemblies with packer assemblies. The applicant of the present invention has developed a quick change mounting bracket which, with the insertion or removal of a single pin, allows harrow assemblies or packer assemblies to be quickly mounted to the rear of a cultivator to perform the different tasks, i.e. direct seeding with on-row packing, direct seeding with sweeps and mounted harrows to kill weeds during seeding, or general tillage.
If harrows are used while direct seeding, a further implement known as a coiled packer can be attached to the rear of the cultivator and towed behind the harrows.
One of the problems encountered, however, with attempting to use harrows or packers on the same implement is that packers need a downward force more than double that of harrows. If packers do not have a sufficient downward force to secure the seed into the soil, poor germination will result. Research has shown that packing pressures from 0.5 pounds per square inch to 5 pounds per square inch consistently give the best crop emergence results.
Packing pressures must also be varied according to the type of soil or moisture conditions. The problems of over compaction of clay soils manifest in two ways; 1) the packer wheel tracks will become smeared or glazed over so that when the soil dries, it bakes too hard to allow normal plant emergence; 2) over compaction also causes soil moisture to be lost through evaporation and the result is a crack in the bottom of a packer wheel track. Once the crack commences the rate of moisture loss increases significantly so that the area around the seed dries out before germination occurs. To prevent moisture loss through capillary action, it is recommended that the soil density above the seed be lower than the soil density below the seed. Thus a need exists to select a correct packing pressure to avoid crop emergence problems.
On the other hand, if harrows are employed with the same downward force as when packers are used, they will become clogged with the left over stubble or straw in the field.
It is therefore, an object of the present invention to provide a combination cultivator/seeder device equipped with easily connected changeable harrows or packers with an adjustment mechanism which can appropriately vary the downward force on said harrows or packers.
It is a further object of the present invention to provide a combination farm implement adaptable for seeding or complete tillage ability.